VLDB 2026 Research / reviewers in the wild / expert
Qizheng Zhang
dblp:271/9220
· DBLP profile ↗
9ranked-venue papers
2as first author
8since 2021 · last 2025
0009-0009-3208-4601ORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Systems, architecture and hardware · 3 · 3 since 2021Computer networks · 3 · 2 since 2021Artificial intelligence and machine learning · 2 · 1 first-author · 2 since 2021Software engineering, systems software and programming languages · 2 · 1 first-author · 2 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2025 | CacheBlend: Fast Large Language Model Serving for RAG with Cached Knowledge FusionabstractLarge language models (LLMs) often incorporate multiple text chunks in their inputs to provide the necessary contexts. To speed up the prefill of the long LLM inputs, one can pre-compute the KV cache of a text and re-use the KV cache when the context is reused as the prefix of another LLM input. However, the reused text chunks are not always the input prefix, which makes precomputed KV caches not directly usable since they ignore the text's cross-attention with the preceding texts. Thus, the benefits of reusing KV caches remain largely unrealized. Hanchen Li, Yuhan Liu 0004, Siddhant Ray, Yihua Cheng, Qizheng Zhang, Kuntai Du, Shan Lu 0001, Junchen Jiang |
EuroSys | 6 |
| 2025 | LowRA: Accurate and Efficient LoRA Fine-Tuning of LLMs under 2 BitsabstractFine-tuning large language models (LLMs) is increasingly costly as models scale to hundreds of billions of parameters, and even parameter-efficient fine-tuning (PEFT) methods like LoRA remain resource-intensive. We introduce LowRA, the first framework to enable LoRA fine-tuning below 2 bits per parameter with minimal performance loss. LowRA optimizes fine-grained quantization—mapping, threshold selection, and precision assignment—while leveraging efficient CUDA kernels for scalable deployment. Extensive evaluations across 4 LLMs and 4 datasets show that LowRA achieves a superior performance–precision trade-off above 2 bits and remains accurate down to 1.15 bits, reducing memory usage by up to 50%. Our results highlight the potential of ultra-low-bit LoRA fine-tuning for resource-constrained environments. Zikai Zhou, Qizheng Zhang, Hermann Kumbong, Kunle Olukotun |
ICML | 2 |
| 2025 | Agentic Plan Caching: Test-Time Memory for Fast and Cost-Efficient LLM AgentsabstractLLM-based agent applications have shown increasingly remarkable capabilities in complex workflows but incur substantial costs and latency due to extensive planning and reasoning requirements.
Existing LLM caching techniques (like context caching and semantic caching), primarily designed for serving chatbots, are insufficient for agent applications where outputs depend on external data and environmental contexts.
We propose **Agentic Plan Caching (APC)**, a novel **test-time memory** that extracts, stores, adapts, and reuses structured plan templates from planning stages of agent applications across semantically similar tasks to reduce the cost and latency of serving.
Unlike traditional semantic caching, our system extracts plan templates from completed agent executions at test-time, employs keyword extraction to match new requests against cached plans, and utilizes lightweight models to adapt these templates to task-specific plans with contexts.
Evaluation across multiple real-world agent applications shows that our system can reduce costs by 50.31\% and latency by 27.28\% on average while maintaining performance, offering a more efficient solution for serving LLM-based agents that complements existing LLM serving infrastructures. Qizheng Zhang, Michael Wornow, Kunle Olukotun |
NeurIPS | 1 |
| 2024 | The Dataflow Abstract Machine Simulator FrameworkabstractThe growing interest in novel dataflow architectures and streaming execution paradigms has created the need for a simulator optimized for modeling dataflow systems. To fill this need, we present three new techniques that make it feasible to simulate complex systems consisting of thousands of components. First, we introduce an interface based on Communicating Sequential Processes which allows users to simultaneously describe functional and timing characteristics. Second, we introduce a scalable point-to-point synchronization scheme that avoids global synchronization. Finally, we demonstrate a technique to exploit slack in the simulated system, such as FIFOs, to increase simulation parallelism. We implement these techniques in the Dataflow Machine (DAM), a parallel simulator framework for dataflow systems. We demonstrate the benefits of using DAM by highlighting three case studies using the framework. First, we use DAM directly as an exploration tool for streaming algorithms on dataflow hardware. We simulate two different implementations of the attention algorithm used in large language models, and use DAM to show that the second implementation only requires a constant amount of local memory. Second, we re-implement a simulator for a sparse tensor algebra accelerator, resulting in $57 \%$ less code and a simulation speedup of up to four orders of magnitude. Finally, we demonstrate a general technique for time-multiplexing real hardware to simulate multiple virtual copies of the hardware using DAM. Nathan Zhang, Rubens Lacouture, Gina Sohn, Paul Mure, Qizheng Zhang, Fredrik Kjolstad, Kunle Olukotun |
ISCA | 5 |
| 2024 | GRACE: Loss-Resilient Real-Time Video through Neural Codecs
Yihua Cheng, Hanchen Li, Anton Arapin, Qizheng Zhang, Yuhan Liu 0004, Kuntai Du, Francis Y. Yan, Amrita Mazumdar, Nick Feamster, Junchen Jiang |
NSDI | 6 |
| 2024 | Caravan: Practical Online Learning of In-Network ML Models with Labeling Agents
Qizheng Zhang, Ali Imran 0005, Enkeleda Bardhi, Tushar Swamy, Nathan Zhang, Muhammad Shahbaz 0001, Kunle Olukotun |
OSDI | 1 |
| 2024 | CacheGen: KV Cache Compression and Streaming for Fast Large Language Model ServingabstractAs large language models (LLMs) take on complex tasks, their inputs are supplemented with longer contexts that incorporate domain knowledge. Yet using long contexts is challenging as nothing can be generated until the whole context is processed by the LLM. While the context-processing delay can be reduced by reusing the KV cache of a context across different inputs, fetching the KV cache, which contains large tensors, over the network can cause high extra network delays. Yuhan Liu 0004, Hanchen Li, Yihua Cheng, Siddhant Ray, Qizheng Zhang, Kuntai Du, Shan Lu 0001, Ganesh Ananthanarayanan, Michael Maire, Henry Hoffmann, Ari Holtzman, Junchen Jiang |
SIGCOMM | 6 |
| 2023 | OneAdapt: Fast Adaptation for Deep Learning Applications via BackpropagationabstractDeep learning inference on streaming media data, such as object detection in video or LiDAR feeds and text extraction from audio waves, is now ubiquitous. To achieve high inference accuracy, these applications typically require significant network bandwidth to gather high-fidelity data and extensive GPU resources to run deep neural networks (DNNs). While the high demand for network bandwidth and GPU resources could be substantially reduced by optimally adapting the configuration knobs, such as video resolution and frame rate, current adaptation techniques fail to meet three requirements simultaneously: adapt configurations (i) with minimum extra GPU or bandwidth overhead (ii) to reach near-optimal decisions based on how the data affects the final DNN's accuracy, and (iii) do so for a range of configuration knobs. This paper presents OneAdapt, which meets these requirements by leveraging a gradient-ascent strategy to adapt configuration knobs. The key idea is to embrace DNNs' differentiability to quickly estimate the accuracy's gradient to each configuration knob, called AccGrad. Specifically, OneAdapt estimates AccGrad by multiplying two gradients: InputGrad (i.e., how each configuration knob affects the input to the DNN) and DNNGrad (i.e., how the DNN input affects the DNN inference output). We evaluate OneAdapt across five types of configurations, four analytic tasks, and five types of input data. Compared to state-of-the-art adaptation schemes, OneAdapt cuts bandwidth usage and GPU usage by 15-59% while maintaining comparable accuracy or improves accuracy by 1-5% while using equal or fewer resources. Kuntai Du, Yuhan Liu 0004, Yitian Hao, Qizheng Zhang, Ganesh Ananthanarayanan, Junchen Jiang |
SoCC | 4 |
| 2020 | Server-Driven Video Streaming for Deep Learning InferenceabstractVideo streaming is crucial for AI applications that gather videos from sources to servers for inference by deep neural nets (DNNs). Unlike traditional video streaming that optimizes visual quality, this new type of video streaming permits aggressive compression/pruning of pixels not relevant to achieving high DNN inference accuracy. However, much of this potential is left unrealized, because current video streaming protocols are driven by the video source (camera) where the compute is rather limited. We advocate that the video streaming protocol should be driven by real-time feedback from the server-side DNN. Our insight is two-fold: (1) server-side DNN has more context about the pixels that maximize its inference accuracy; and (2) the DNN's output contains rich information useful to guide video streaming. We present DDS (DNN-Driven Streaming), a concrete design of this approach. DDS continuously sends a low-quality video stream to the server; the server runs the DNN to determine where to re-send with higher quality to increase the inference accuracy. We find that compared to several recent baselines on multiple video genres and vision tasks, DDS maintains higher accuracy while reducing bandwidth usage by upto 59% or improves accuracy by upto 9% with no additional bandwidth usage. Kuntai Du, Ahsan Pervaiz, Aakanksha Chowdhery, Qizheng Zhang, Henry Hoffmann, Junchen Jiang |
SIGCOMM | 5 |